The Iron Front (German: Eiserne Front) was a German underground paramilitary organization in the Weimar Republic which consisted of social democrats, trade unionists, and democratic socialists. Its main goal was to defend liberal democracy against totalitarian ideologies, right-wing and far-left politics.
The Iron Front chiefly opposed the Sturmabteilung (SA) wing of the Nazi Party and the Antifaschistische Aktion wing of the Communist Party of Germany. Formally independent, it was intimately associated with the Social Democratic Party of Germany (SPD). The Three Arrows, originally designed for the Iron Front, became a well-known social democratic symbol representing resistance against monarchism, Nazism, and communism during the parliamentary elections in November 1932.